Monthly 16×16 Sudoku leaderboard

Register for free

Here are some great benefits to registering for free at Puzzle Madness!

Save your progress on any puzzle at any time.

We will keep track which puzzles you have done, so that you don't end up doing the same puzzle twice.

It's free!

How to play

This page requires a modern browser with Javascript enabled. To play our Sudoku puzzles online, do the following

This page will automatically play our 16×16 Giant Sudoku puzzle of the day. If you wish to play a 16×16 Giant Sudoku from a different day, go to the archive page.

To enter a number/letter, click on a cell and type in the number/letter you want. Since our Giant Sudoku grids have more than 9 numbers, we also use A-C (12*12 grids), and A-F (16*16 grids).

To enter pencil marks, press Shift, Ctrl, or Alt as you enter the number/letter; Shift is usually the best to use as the other keys can do other things on your browser. To remove the pencil mark, repeat the process again!

Use the buttons on the right side to reset the grid, automatically generate and clear the pencil marks.